Are We Forgetting the Lessons From the Accident at Three Mile Island Unit 2, March 1979: A Case Study

The accident at Three Mile Island Unit 2 in March 1979 resulted in major changes to the way emergency procedures were written and operators were trained at nuclear commercial electric generating units. These changes had a major impact on the public health risk of nuclear electric generating units. The record over the last 20 years has been excellent. For approximately 2000 reactor years of operation since 1979, there have been no accidents equivalent to TMI Unit 2 in the USA. Other factors have had an influence on this excellent record but it is clear that more efficient emergency procedures and better operator training had a significant impact on the excellent record achieved over the last 20 plus years. Abnormal events still occur at the nuclear commercial electric generating units in the USA and these events have the potential for causing damage to the reactor core. In some cases, the emergency procedures used in abnormal events and the training received by the operators of the nuclear units have not been based on the lessons learned from the accident at Three Mile Island. The following paper describes one such case. It is clear to the authors of this paper that further changes should be made to make sure that the lessons learned from the accident at Three Mile Island Unit 2 in 1979 are implemented and not forgotten.